ui/views/controls/glow_hover_controller.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "ui/views/controls/glow_hover_controller.h"
   6
   7 #include "third_party/skia/include/effects/SkGradientShader.h"
   8 #include "ui/gfx/canvas.h"
   9 #include "ui/gfx/image/image_skia.h"
  10 #include "ui/gfx/image/image_skia_operations.h"
  11 #include "ui/views/view.h"
  12
  13 namespace views {
  14
  15 // Amount to scale the opacity.
  16 static const double kTrackOpacityScale = 0.5;
  17 static const double kHighlightOpacityScale = 1.0;
  18
  19 // How long the hover state takes.
  20 static const int kTrackHoverDurationMs = 400;
  21
  22 GlowHoverController::GlowHoverController(views::View* view)
  23     : view_(view),
  24       animation_(this),
  25       opacity_scale_(kTrackOpacityScale) {
  26   animation_.set_delegate(this);
  27 }
  28
  29 GlowHoverController::~GlowHoverController() {
  30 }
  31
  32 void GlowHoverController::SetAnimationContainer(
  33     gfx::AnimationContainer* container) {
  34   animation_.SetContainer(container);
  35 }
  36
  37 void GlowHoverController::SetLocation(const gfx::Point& location) {
  38   location_ = location;
  39   if (ShouldDraw())
  40     view_->SchedulePaint();
  41 }
  42
  43 void GlowHoverController::Show(Style style) {
  44   switch (style) {
  45     case SUBTLE:
  46       opacity_scale_ = kTrackOpacityScale;
  47       animation_.SetSlideDuration(kTrackHoverDurationMs);
  48       animation_.SetTweenType(gfx::Tween::EASE_OUT);
  49       animation_.Show();
  50       break;
  51     case PRONOUNCED:
  52       opacity_scale_ = kHighlightOpacityScale;
  53       // Force the end state to show immediately.
  54       animation_.Show();
  55       animation_.End();
  56       break;
  57   }
  58 }
  59
  60 void GlowHoverController::Hide() {
  61   animation_.SetTweenType(gfx::Tween::EASE_IN);
  62   animation_.Hide();
  63 }
  64
  65 void GlowHoverController::HideImmediately() {
  66   if (ShouldDraw())
  67     view_->SchedulePaint();
  68   animation_.Reset();
  69 }
  70
  71 double GlowHoverController::GetAnimationValue() const {
  72   return animation_.GetCurrentValue();
  73 }
  74
  75 bool GlowHoverController::ShouldDraw() const {
  76   return animation_.IsShowing() || animation_.is_animating();
  77 }
  78
  79 void GlowHoverController::Draw(gfx::Canvas* canvas,
  80                                const gfx::ImageSkia& mask_image) const {
  81   if (!ShouldDraw())
  82     return;
  83
  84   // Draw a radial gradient to hover_canvas.
  85   gfx::Canvas hover_canvas(gfx::Size(mask_image.width(), mask_image.height()),
  86                            canvas->image_scale(),
  87                            false);
  88
  89   // Draw a radial gradient to hover_canvas.
  90   int radius = view_->width() / 3;
  91
  92   SkPoint center_point;
  93   center_point.iset(location_.x(), location_.y());
  94   SkColor colors[2];
  95   int hover_alpha =
  96       static_cast<int>(255 * opacity_scale_ * animation_.GetCurrentValue());
  97   colors[0] = SkColorSetARGB(hover_alpha, 255, 255, 255);
  98   colors[1] = SkColorSetARGB(0, 255, 255, 255);
  99   skia::RefPtr<SkShader> shader = skia::AdoptRef(
 100       SkGradientShader::CreateRadial(
 101           center_point, SkIntToScalar(radius), colors, NULL, 2,
 102           SkShader::kClamp_TileMode));
 103   // Shader can end up null when radius = 0.
 104   // If so, this results in default full tab glow behavior.
 105   if (shader) {
 106     SkPaint paint;
 107     paint.setStyle(SkPaint::kFill_Style);
 108     paint.setAntiAlias(true);
 109     paint.setShader(shader.get());
 110     hover_canvas.DrawRect(gfx::Rect(location_.x() - radius,
 111                                     location_.y() - radius,
 112                                     radius * 2, radius * 2), paint);
 113   }
 114   gfx::ImageSkia result = gfx::ImageSkiaOperations::CreateMaskedImage(
 115       gfx::ImageSkia(hover_canvas.ExtractImageRep()), mask_image);
 116   canvas->DrawImageInt(result, (view_->width() - mask_image.width()) / 2,
 117                        (view_->height() - mask_image.height()) / 2);
 118 }
 119
 120 void GlowHoverController::AnimationEnded(const gfx::Animation* animation) {
 121   view_->SchedulePaint();
 122 }
 123
 124 void GlowHoverController::AnimationProgressed(const gfx::Animation* animation) {
 125   view_->SchedulePaint();
 126 }
 127
 128 }  // namespace views